Buggy code:
public static void assertTokenStreamContents ( TokenStream ts , String [ ] output , int [ ] startOffsets , int [ ] endOffsets , int [ ] posIncrements , Integer finalOffset ) throws IOException { } public static void assertTokenStreamContents ( TokenStream ts , String [ ] output , int [ ] startOffsets , int [ ] endOffsets , int [ ] posIncrements , int [ ] posLengths , Integer finalOffset ) throws IOException { } public static void assertAnalyzesTo ( Analyzer a , String input , String [ ] output , int [ ] startOffsets , int [ ] endOffsets , String [ ] types , int [ ] posIncrements ) throws IOException { } public static void assertAnalyzesTo ( Analyzer a , String input , String [ ] output , int [ ] startOffsets , int [ ] endOffsets , String [ ] types , int [ ] posIncrements , int [ ] posLengths ) throws IOException { } public static void assertAnalyzesTo ( Analyzer a , String input , String [ ] output , int [ ] startOffsets , int [ ] endOffsets , String [ ] types , int [ ] posIncrements , int [ ] posLengths , boolean offsetsAreCorrect ) throws IOException { } public static void assertAnalyzesTo ( Analyzer a , String input , String [ ] output ) throws IOException { } public static void assertAnalyzesTo ( Analyzer a , String input , String [ ] output , String [ ] types ) throws IOException { } public static void assertAnalyzesTo ( Analyzer a , String input , String [ ] output , int [ ] posIncrements ) throws IOException { } public static void assertAnalyzesToPositions ( Analyzer a , String input , String [ ] output , int [ ] posIncrements , int [ ] posLengths ) throws IOException { } public static void assertAnalyzesTo ( Analyzer a , String input , String [ ] output , int [ ] startOffsets , int [ ] endOffsets ) throws IOException { } public static void assertAnalyzesTo ( Analyzer a , String input , String [ ] output , int [ ] startOffsets , int [ ] endOffsets , int [ ] posIncrements ) throws IOException { } public static void assertAnalyzesToReuse ( Analyzer a , String input , String [ ] output , int [ ] startOffsets , int [ ] endOffsets , String [ ] types , int [ ] posIncrements ) throws IOException { } public static void assertAnalyzesToReuse ( Analyzer a , String input , String [ ] output ) throws IOException { } public static void assertAnalyzesToReuse ( Analyzer a , String input , String [ ] output , String [ ] types ) throws IOException { } public static void assertAnalyzesToReuse ( Analyzer a , String input , String [ ] output , int [ ] posIncrements ) throws IOException { } public static void assertAnalyzesToReuse ( Analyzer a , String input , String [ ] output , int [ ] startOffsets , int [ ] endOffsets ) throws IOException { } public static void assertAnalyzesToReuse ( Analyzer a , String input , String [ ] output , int [ ] startOffsets , int [ ] endOffsets , int [ ] posIncrements ) throws IOException { } public static void checkOneTerm ( Analyzer a , final String input , final String expected ) throws IOException { } public static void checkOneTermReuse ( Analyzer a , final String input , final String expected ) throws IOException { } public static void checkRandomData ( Random random , Analyzer a , int iterations ) throws IOException { } public static void checkRandomData ( Random random , Analyzer a , int iterations , int maxWordLength ) throws IOException { } public static void checkRandomData ( Random random , Analyzer a , int iterations , boolean simple ) throws IOException { } static class AnalysisThread extends Thread { final int iterations ; final int maxWordLength ; final long seed ; final Analyzer a ; final boolean useCharFilter ; final boolean simple ; final boolean offsetsAreCorrect ; public boolean failed ; AnalysisThread ( long seed , Analyzer a , int iterations , int maxWordLength , boolean useCharFilter , boolean simple , boolean offsetsAreCorrect ) { } @ Override public void run ( ) { } } public static void checkRandomData ( Random random , Analyzer a , int iterations , int maxWordLength , boolean simple ) throws IOException { } public static void checkRandomData ( Random random , Analyzer a , int iterations , int maxWordLength , boolean simple , boolean offsetsAreCorrect ) throws IOException { long seed = random . nextLong ( ) ; boolean useCharFilter = random . nextBoolean ( ) ; BaseTokenStreamTestCase . checkRandomData ( new Random ( seed ) , a , iterations , maxWordLength , useCharFilter , simple , offsetsAreCorrect ) ; <START_BUG> int numThreads = _TestUtil . nextInt ( random , 4 , 8 ) ; <END_BUG> BaseTokenStreamTestCase . AnalysisThread [ ] threads = new BaseTokenStreamTestCase . AnalysisThread [ numThreads ] ; for ( int i = 0 ; i < ( threads . length ) ; i ++ ) { threads [ i ] = new BaseTokenStreamTestCase . AnalysisThread ( seed , a , iterations , maxWordLength , useCharFilter , simple , offsetsAreCorrect ) ; } for ( int i = 0 ; i < ( threads . length ) ; i ++ ) { threads [ i ] . start ( ) ; } for ( int i = 0 ; i < ( threads . length ) ; i ++ ) { try { threads [ i ] . join ( ) ; } catch ( InterruptedException e ) { throw new RuntimeException ( e ) ; } } for ( int i = 0 ; i < ( threads . length ) ; i ++ ) { if ( threads [ i ] . failed ) { throw new RuntimeException ( "some<seq2seq4repair_space>thread(s)<seq2seq4repair_space>failed" ) ;

Fix:
int numThreads = _TestUtil . nextInt ( random , 2 , 4 ) ;